Seven Dwarves

Seven Dwarves gets +1/+1 for each other creature named Seven Dwarves you control.
A deck can have up to seven cards named Seven Dwarves.

Mirror March

Whenever a nontoken creature you control enters, flip a coin until you lose a flip. For each flip you won, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Mirrormade

You may have Mirrormade enter as a copy of any artifact or enchantment on the battlefield.